drm/panthor: Call panthor_sched_post_reset() even if the reset failed

We need to undo what was done in panthor_sched_pre_reset() even if the
reset failed. We just flag all previously running groups as terminated
when that happens to unblock things.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240502183813.1612017-5-boris.brezillon@collabora.com

drm/panthor: Force an immediate reset on unrecoverable faults

If the FW reports an unrecoverable fault, we need to reset the GPU
before we can start re-using it again.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240502183813.1612017-2-boris.brezillon@collabora.com

drm/panthor: Fix IO-page mmap() for 32-bit userspace on 64-bit kernel

When mapping an IO region, the pseudo-file offset is dependent on the
userspace architecture. panthor_device_mmio_offset() abstracts that
away for us by turning a userspace MMIO offset into its kernel
equivalent, but we were not updating vm_area_struct::vm_pgoff
accordingly, leading us to attach the MMIO region to the wrong file
offset.

This has implications when we start mixing 64 bit and 32 bit apps, but
that's only really a problem when we start having more that 2^43 bytes of
memory allocated, which is very unlikely to happen.

What's more problematic is the fact this turns our
unmap_mapping_range(DRM_PANTHOR_USER_MMIO_OFFSET) calls, which are
supposed to kill the MMIO mapping when entering suspend, into NOPs.
Which means we either keep the dummy flush_id mapping active at all
times, or we risk a BUS_FAULT if the MMIO region was mapped, and the
GPU is suspended after that.

Solve that by patching vm_pgoff early in panthor_mmap(). With
this in place, we no longer need the panthor_device_mmio_offset()
helper.

v3:
- No changes

v2:
- Kill panthor_device_mmio_offset()

Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Reported-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reported-by: Lukas F. Hartmann <lukas@mntmn.com>
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/10835
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240326111205.510019-1-boris.brezillon@collabora.com

drm/panthor: Don't use virt_to_pfn()

virt_to_pfn() isn't available on x86 (except to xen) so breaks
COMPILE_TEST builds. Avoid its use completely by instead storing the
struct page pointer allocated in panthor_device_init() and using
page_to_pfn() instead.

Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240318145119.368582-1-steven.price@arm.com

drm/panthor: Fix the CONFIG_PM=n case

Putting a hard dependency on CONFIG_PM is not possible because of a
circular dependency issue, and it's actually not desirable either. In
order to support this use case, we forcibly resume at init time, and
suspend at unplug time.

v2:
- Drop the #ifdef CONFIG_PM section around panthor_pm_ops's definition

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403031944.EOimQ8WK-lkp@intel.com/
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240318153117.1321544-1-boris.brezillon@collabora.com

Revert "drm/panthor: Fix undefined panthor_device_suspend/resume symbol issue"

This reverts commit 674dc7f61aefea81901c21402946074927e63f1a.

The commit causes a recursive dependency in kconfig:

drivers/iommu/Kconfig:14:error: recursive dependency detected!
drivers/iommu/Kconfig:14: symbol IOMMU_SUPPORT is selected by DRM_PANTHOR
drivers/gpu/drm/panthor/Kconfig:3: symbol DRM_PANTHOR depends on PM
kernel/power/Kconfig:183: symbol PM is selected by PM_SLEEP
kernel/power/Kconfig:117: symbol PM_SLEEP depends on HIBERNATE_CALLBACKS
kernel/power/Kconfig:35: symbol HIBERNATE_CALLBACKS is selected by XEN_SAVE_RESTORE
arch/x86/xen/Kconfig:67: symbol XEN_SAVE_RESTORE depends on XEN
arch/x86/xen/Kconfig:6: symbol XEN depends on PARAVIRT
arch/x86/Kconfig:781: symbol PARAVIRT is selected by HYPERV
drivers/hv/Kconfig:5: symbol HYPERV depends on X86_LOCAL_APIC
arch/x86/Kconfig:1106: symbol X86_LOCAL_APIC depends on X86_UP_APIC
arch/x86/Kconfig:1081: symbol X86_UP_APIC prompt is visible depending on PCI_MSI
drivers/pci/Kconfig:39: symbol PCI_MSI is selected by AMD_IOMMU
drivers/iommu/amd/Kconfig:3: symbol AMD_IOMMU depends on IOMMU_SUPPORT
For a resolution refer to Documentation/kbuild/kconfig-language.rst
subsection "Kconfig recursive dependency limitations"

Fixes: 674dc7f61aef ("drm/panthor: Fix undefined panthor_device_suspend/resume symbol issue")
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Steven Price <steven.price@arm.com>
Acked-by: Boris Brezillon <boris.brezillon@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240311111619.249776-1-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drm/panthor: Fix undefined panthor_device_suspend/resume symbol issue

panthor_device_resume/suspend() are only compiled when CONFIG_PM is
enabled but panthro_drv.c doesn't use the pm_ptr() macro to conditionally
discard resume/suspend assignments, which causes undefined symbol
errors at link time when !PM.

We could fix that by using pm_ptr(), but supporting the !PM case makes
little sense (the whole point of these embedded GPUs is to be low power,
so proper PM is a basic requirement in that case). So let's just enforce
the presence of CONFIG_PM with a Kconfig dependency instead.

If someone needs to relax this dependency, it can be done in a follow-up.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403031944.EOimQ8WK-lkp@intel.com/
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240304090812.3941084-4-boris.brezillon@collabora.com

drm/panthor: Explicitly include mm.h for the {virt, __phys)_to_pfn() defs

Something on arm[64] must be including <asm/page.h>, but things fail
to compile on sparc64. Make sure this header is included (through
linux/mm.h) so this driver can be compile-tested on all supported
architectures.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403031142.Vl4pW7X6-lkp@intel.com/
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240304090812.3941084-3-boris.brezillon@collabora.com

drm/panthor: Add the device logical block

The panthor driver is designed in a modular way, where each logical
block is dealing with a specific HW-block or software feature. In order
for those blocks to communicate with each other, we need a central
panthor_device collecting all the blocks, and exposing some common
features, like interrupt handling, power management, reset, ...

This what this panthor_device logical block is about.

v6:
- Add Maxime's and Heiko's acks
- Keep header inclusion alphabetically ordered

v5:
- Suspend the MMU/GPU blocks if panthor_fw_resume() fails in
panthor_device_resume()
- Move the pm_runtime_use_autosuspend() call before drm_dev_register()
- Add Liviu's R-b

v4:
- Check drmm_mutex_init() return code
- Fix panthor_device_reset_work() out path
- Fix the race in the unplug logic
- Fix typos
- Unplug blocks when something fails in panthor_device_init()
- Add Steve's R-b

v3:
- Add acks for the MIT+GPL2 relicensing
- Fix 32-bit support
- Shorten the sections protected by panthor_device::pm::mmio_lock to fix
lock ordering issues.
- Rename panthor_device::pm::lock into panthor_device::pm::mmio_lock to
better reflect what this lock is protecting
- Use dev_err_probe()
- Make sure we call drm_dev_exit() when something fails half-way in
panthor_device_reset_work()
- Replace CSF_GPU_LATEST_FLUSH_ID_DEFAULT with a constant '1' and a
comment to explain. Also remove setting the dummy flush ID on suspend.
- Remove drm_WARN_ON() in panthor_exception_name()
- Check pirq->suspended in panthor_xxx_irq_raw_handler()

Co-developed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Steven Price <steven.price@arm.com> # MIT+GPL2 relicensing,Arm
Acked-by: Grant Likely <grant.likely@linaro.org> # MIT+GPL2 relicensing,Linaro
Acked-by: Boris Brezillon <boris.brezillon@collabora.com> # MIT+GPL2 relicensing,Collabora
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20240229162230.2634044-4-boris.brezillon@collabora.com